Various types of surface cleaning apparatus are known. These include upright surface cleaning apparatus, canister surface cleaning apparatus, stick surface cleaning apparatus and central vacuum systems. Typically, a surface cleaning apparatus has a surface cleaning head with an inlet. For example, an upright surface cleaning apparatus typically comprises an upright section containing at least an air treatment member that is pivotally mounted to a surface cleaning head. A canister surface cleaning apparatus typically comprises a canister body containing at least an air treatment member and a suction motor that is connected to a surface cleaning head by a flexible hose and a handle. Such designs are advantageous as they permit some of the operating components, and optionally all of the operating components (i.e., the suction motor and the air treatment members) to be placed at a location other than the surface cleaning head. This enables the surface cleaning head to be lighter and smaller. Reducing the weight of the surface cleaning head may increase its maneuverability. Also, reducing the height of the surface cleaning head enables the surface cleaning head to clean under furniture having a lower ground clearance.
Another type of surface cleaning apparatus is the all in the head surface cleaning apparatus. An all in the head surface cleaning apparatus has the suction motor and the air treatment members (e.g., one or more cyclones) positioned in the surface cleaning head. However, for various reasons, the all in the head vacuum cleaner has not been widely accepted by consumers.
U.S. Pat. Nos. 5,699,586; 6,012,200; 6,442,792; 7,013,528; US 2004/0134026; US 2006/0156509; and, US 2009/0056060 disclose an all in the head vacuum cleaner wherein the surface cleaning head is wedge shaped (i.e., the height of the surface cleaning head increases from the front end to the rear end). Accordingly, the height at the rear end limits the extent to which the surface cleaning head may travel under furniture. If the height is too tall, then only the front portion of the surface cleaning head may be able to be placed under furniture, thereby limiting the ability of the surface cleaning apparatus to clean under furniture.
U.S. Pat. No. 5,909,755 discloses an all in the head vacuum cleaner. However, this design has limited filtration ability. As set out in the abstract, the design uses a suction motor to draw in air having entrained particulate matter through a filter to thereby treat the air. Accordingly, while the design is not wedge shaped, it relies upon a filter to treat the air.